Automatic yielding pressure-bars for sandpapering-machines.



UNITED STATES PATE T Patented June 30, 1903.

OFFICE.

WELL &WATERS CO., ACORPORATION OF PENNSYLVANIA.

AUTOMATIC YIELDING PRESSURE-BARS FOR SANDPAPERlNG-MACHINES.

SPECIFICATION forming part of Letters Patent No. 732,381, dated June 30, 1903. Application filed September 6,1902. Serial No. 122,308. (No model.)

To aZZ whom it may concern.-

Be it known that I, CHARLES C. STUART, a citizen of the United States, residing at Campville, in the countyof Litchfield and State of Connecticut, have invented certain newand useful Improvements in Automatic Yielding Pressure-Bars for Sandpapering-Machines, of which the following is a specification.

My invention relates to sandpapering-machines, and has for its object means for antomatically holding the material operated on by the sandpapered drum firmly to the traveling bed or platen, on which it lies while be ing passed under the sandpapered drum. To obtain a true, even, and non-wavy surface and to securely hold Warped or twisted stock, it is essential that the stock or object being sandpapered be held firmly to the platen in manner to prevent chattering, which will cause the finished surface to be wavy and uneven, whereas if the stock is firmly held to its bed an even surface will be produced, which is the object sought in this class of machines.

While I have shown only one drum to illustrate theapplication of the pressure-bars in connection therewith, it will be evident that the number of drums, with their pressurebars, can readily be increased, if desired.

My invention isillustrated in the accompanying drawings, wherein Figure 1 is a plan or top View of a sandpaper-drum, with its complement of pressurebars, one end onlyof the drum and bars being shown. As both ends are alike, this is deemed suflicient for a thorough understanding of the devices. Fig. 2 is a cross-section on line X X,'Fig. 1. Fig. 3 is an enlarged top view of one of the pressure-bars. Fig. 4 is an end view of Fig. 3.

Similar figures of reference indicate similar parts throughout the views.

The drum 1 has a shaft 2, mounted in bearings 3, supported in a framework 4:, having cross-pieces 5 5, and pulleys 6 on the shaft are run by belt 7 from any suitable source of power. A table or platen 8 passes under drum 1, it being mounted upon suitable means for its propulsion, and the stock 9 to be worked or sandpapered is placed upon its top. As my mechanism is suitable to be adapted to many movable tables with different moving means, a generalshowiug only, as I have illustrated, is deemed sufiicient to show the application of the pressure-bars in conjunction with a drum or a series of drums having means to secure sandpaper thereon for abrasive purposes. At either side of drum 1 are placed pressure-bars 1O 11 on rods 12 13 of circular cross-section,which construction permits the bars to partially rotate on the rods, the rods being cut away at their ends to form seats 14, which are firmly secured to lugs 15 of cross-pieces 5 by bolts 16 or equivalent means for their security. Where a series of drums 'are employed, simple modifications only will be necessary to adapt the fastenings to the framework. The pressure-bars 10 11 have projecting edges 17 reaching under the drum to near its lower central point and thinly formed for such purpose. As heretofore stated, the pressurebars 10 11 are placed on rods 12 13, the bars snugly fitting the rods, but free to rotatably move thereon, and to avoid undue expense in preparation a series of integral strap formations 18 are made, whereby the bars are secured on the rods. At necessary intervals lengthwise of the bars are pockets 19, in which are placed coiled springs 20, which at their outer ends abut flanges 21 of cross-pieces 5, thus pressing projecting edges 17 to the stock 9 on platen 8. To limit the downward movement of the pressure-bar so that it will be suitable to thin and light or thick and heavy stock, adj usting-screws 22 are inserted in the heels 23 of the bars, and at their outer ends they abut flanges 24. of cross pieces 5, and check-nuts 25 lock the screws when adjusted.

I claim 1. In a sandpapering-machine, an abrasive drum, means for its rotatable support, means for its rotation, means to pass stock under the drum, and pressure-bars pivotally supported, resilient means adapted to automatically press the bars upon the stock at each side of the drum and throughout its length, and adj ustable means to limit the movement of the bars.

2. In a sandpapering-machine, an abrasive drum rotatably supported above a platen, means for its rotation, rocking pressure-bars IOO pivotallysupported at the sides of the drum, and resilient means to press the bars toward the platen and permit their recession therefrom, and adjustable means to limit their movement.

3. In a sandpapering-machine, an abrasive drum having means for its support and rotation, means to pass stock under the drum, rocking pressure-bars at each side of the drum, and each reaching partially under the drum, adapted to press upon the stock and having means to produce said pressure, and means to limit the movement of the bars and thereby the amount of pressure.

4. In a sandpapering-machine, an abrasive drum fixed in a suitable framework, having means for its rotation, and with a movable platen thereunder, rods of circular cross-section removably fixed upon the framework at each side of the drum, pressure-bars placed thereon,adjacent to the drum aforesaid reaching thereunder and partially rotatable on the rods, resilient means whereby the pressurebars are forced in opposite directions toward the platen aforesaid and permitted to recede therefrom,and adjustable means to limit their movement toward the platen, and also permit their recession therefrom.

5. In a sandpaperingmachine, a framework, an abrasive drum mounted thereon for rotary movement, and means for such movement-,a platen adapted to pass under the drum, pivotally-snpported pressurebars at each side of the drum and formed to reach for a distance under the drum, means to support the bars in manner to permit the part under the drum to move radially toward and from the platen and means controlling said movements.

6. In a sandpapering-machine, a rotatable drum fixed above a horizontally-movable platen, pressure-bars at each side of the drum, above the platen, and adapted to press upon an object resting on the platen, a part of each pressure-bar reaching under the drum, a means of suspension for the pressure-bars whereby their parts under the drum are permitted to oscillate toward and from the platen, a part for the pressurebars extending above their suspensions, at the sides of the dru m, and resilient means actuating said upper part to force it toward the drum and thereby force the part under the drum toward the platen and on the object thereon, and permit a recession of such pressure.

7. In a machine such as described, a drum, pressure-bars at each side of the drum, the said bars having parts reaching under said drum and toward each other, other parts extending upward by the drum, means to suspend the bars for oscillating movement,m cans to press the underreaehing parts downward, and to permit their recession, and means to limit the amount of downward movement, and thereby the pressure.

In testimony whereof I aifix my signature in presence of two witnesses.

CHARLES (3. STUART.

Witnesses:

R. O. WRIGHT, WILLIAM G. STOEVER. 

